If you’re after an Android tab for productivity or typing long emails, consider this impressive and affordable convertible IdeaTab.

For far too long, we’ve seen no real competitor to Asus’ Transformer family, especially the eminently affordable Transformer Pad 300. Now, however, this Android tablet with keyboard base that also incorporates an extra battery and connectivity is about to get some serious competition.

The Lenovo IdeaTab S2110, which we had already heard about last year, is a 10.1in tab with a 1,280 x 800 IPS screen, Qualcomm’s dual-core 1.5GHz S4 Snapdragon processor, 1GB of RAM and up to 32GB of native storage.

The 580g tablet also sports front and rear cameras of 1.3 and 5.0MP respectively with an LED flash for the latter. Connectivity is particularly impressive, far outdoing the Pad 300 with microHDMI, microUSB and Bluetooth 4.0 on the tablet itself, plus a SIM card slot on the 3G model. Considering that Asus still doesn’t offer a 3G Transformer tablet, that’s a pretty significant option.

The keyboard base too offers more, with two rather than just one USB ports, a card reader, and non-proprietary microUSB charging port. More good news comes in (claimed) battery life, which is up to 20hrs with the keyboard base attached (compared to 16 for the Tegra 3-sporting Transformer Pad).

The Lenovo IdeaTab S2110 has gone on sale at the company’s US store at $429 for the basic 16GB tablet or $499 with keyboard dock. Getting the 32GB version will set you back $539 direct, which – considering its advantages – compares favourably to the $520-ish the 32GB Asus Transformer TF300 will set you back with its keyboard. We can only assume UK pricing will be similarly competitive.

Either way, we’ll let you know soon which convertible tablet to go for in our full review.